This invention relates in general to physical therapy exercise and conditioning equipment. In particular, this invention relates to an improved structure for a biomechanical exercise device that increases user comfort and is capable of exercising each ankle quickly and easily.
Various types of physical therapy exercise and conditioning equipment are known in the art. Some devices provide for the specific manipulation of the ankle of the user. One such ankle manipulation device is described and illustrated in U.S. Pat. No. 4,653,748 to Seel et al., which discloses an ankle exercise device that is formed from a flat disc made of a relatively rigid plastic material. The disc includes a first side that is adapted to be engaged by the user to effect movement of a right ankle of the user and a second side that is adapted to be engaged by the user to effect movement of a left ankle. Each side of the Seel et al. disc includes a plurality of indicia (lines) that extend outwardly from a common origin point. The origin point of the indicia are offset relative to the geometric center of the disc, and the shape of the perimeter of the Seel et al. disc is defined by the various indicia emanating from the origin point.
To use the Seel et al. disc, a hemispherical member is initially secured to the side of the ankle exercise device that is opposite of the side that is adapted to be engaged by the user. The hemispherical member is secured to that opposite side at the origin point of the indicia so as to provide a fulcrum point for articulation of the disc. The hemispherical member may further include a cylindrical extension to vary the overall height of the fulcrum. By varying the size of the fulcrum, different angular ranges of motion may be provided for desired ankle exercise routines.
Although the Seel et al. ankle exercise device is effective, it has been found that the rigid flat disc may feel uncomfortable to a user after a period of time. Also, the hemispherical fulcrum of the Seel et al. ankle exercise device must be switched from one side to the other in order to exercise each ankle. Thus, it would be desirable to provide an improved structure for an exercise device that increases user comfort and is capable of exercising each ankle without having to switch the hemispherical fulcrum from one side to the other.